Since archery has again been taken up on the Olympic programme (1972), competitive archery has developed strongly. This has increased the demand for performance and function of the equipment. The development has also influenced the design and rules valid for the target faces with a diameter of 48″/122 cm, which have been used since the first Olympic Games where archery was included (London 1908). The target faces were initially 5-ringed, scoring 9, 7, 5, 3, 1 with a diameter of 244 mm for the “gold” (score 9). The target faces used today are 10-ringed, scoring 10-1 with an “inner-ten” diameter of 61 mm. Of the scoring area for the highest score, i.e. the “gold”, only 1/16th (6.25%) remains. Today's elite archers, however, remarkably often hit the “gold” from the maximum distance of 75 or 90 metres. The accuracy of aim is high. With the scoring area of the target faces reduced, at cases of interference with the bow, a minimal deviation in the flight of the arrow after release of the arrow is desirable.
The arrows, with a shaft of wood, which were used at the Olympic Games 1908 in London, were likely not to have had an initial velocity exceeding 30 metres per second. The arrows used today, however, often have an initial velocity exceeding 70 metres per second, sometimes even 100 metres per second.
At the bottom the vane usually has a longitudinal base, or “foot”, for attachment to the arrow shaft, typically by means of gluing. The vanes are usually made from polymer materials of elastomeric type, e.g. elastomeric plastics, such as for example polyurethane, especially polyether urethane.
Typically three vanes are used for an arrow in archery, but other numbers of vanes are also used, e.g. two, especially for crossbow shooting, but also four, or five vanes are sometimes used for arrows in archery.
It is known that a deviation in the flight of an arrow may occur when the archer has released the arrow at cases of interference of the arrow with the bow after leaving the string.
U.S. Pat. No. 4,615,552 discloses vanes for stabilization of the flight of an arrow after the release. In one embodiment the vane exhibits a saw-teeth profile. In one embodiment the saw-teeth profile has valleys, the depth of which is up to ⅔ of the total height of the fletching vane above its base, and preferably about 40% the total height of the fletching vane above its base.
It has been found that it is possible, at cases of interference between an arrow and the bow, to markedly increase the accuracy of the shooting.
The present invention therefore constitutes an improvement of the vane according to the U.S. Pat. No. 4,615,552.